Blackleg outbreak shows vaccine s value

摘要

A herd stopped vaccinating for blackleg, but came to rue that decision. IT WAS THE END of a hot, humid day in August when John phoned. The summer had been especially rainy, and with all the electrical storms in the area, John had just come in from checking his herd of 35 Charolais X cows and calves. He sounded panicky. "They were all fine three days ago. Tonight there is one dead steer, and two other older calves down and looking like they are heading the same direction. They are three of my best calves".